/***************************************************************************
 *   Copyright (C) 2014 by Eike Hein <hein@kde.org>                   *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA .        *
 ***************************************************************************/

#ifndef POSITIONER_H
#define POSITIONER_H

#include <QAbstractItemModel>

#include "folderplugin_private_export.h"

class FolderModel;

class QTimer;

class FOLDERPLUGIN_TESTS_EXPORT Positioner : public QAbstractItemModel
{
    Q_OBJECT

    Q_PROPERTY(bool enabled READ enabled WRITE setEnabled NOTIFY enabledChanged)
    Q_PROPERTY(FolderModel* folderModel READ folderModel WRITE setFolderModel NOTIFY folderModelChanged)
    Q_PROPERTY(int perStripe READ perStripe WRITE setPerStripe NOTIFY perStripeChanged)
    Q_PROPERTY(QStringList positions READ positions WRITE setPositions NOTIFY positionsChanged)

    public:
        explicit Positioner(QObject *parent = nullptr);
        ~Positioner() override;

        bool enabled() const;
        void setEnabled(bool enabled);

        FolderModel *folderModel() const;
        void setFolderModel(QObject *folderModel);

        int perStripe() const;
        void setPerStripe(int perStripe);

        QStringList positions() const;
        void setPositions(const QStringList &positions);

        Q_INVOKABLE int map(int row) const;

        Q_INVOKABLE int nearestItem(int currentIndex, Qt::ArrowType direction);

        Q_INVOKABLE bool isBlank(int row) const;
        Q_INVOKABLE int indexForUrl(const QUrl &url) const;

        Q_INVOKABLE void setRangeSelected(int anchor, int to);

        Q_INVOKABLE void reset();

        Q_INVOKABLE void move(const QVariantList &moves);

        QHash<int, QByteArray> roleNames() const override;

        QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
        QModelIndex parent(const QModelIndex &index) const override;

        QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const override;

        int rowCount(const QModelIndex &parent = QModelIndex()) const override;
        int columnCount(const QModelIndex &parent = QModelIndex()) const override;

#ifdef BUILD_TESTING
        QHash<int, int> proxyToSourceMapping() const {
            return m_proxyToSource;
        }
        QHash<int, int> sourceToProxyMapping() const {
            return m_sourceToProxy;
        }
#endif

    Q_SIGNALS:
        void enabledChanged() const;
        void folderModelChanged() const;
        void perStripeChanged() const;
        void positionsChanged() const;

    private Q_SLOTS:
        void updatePositions();
        void sourceStatusChanged();
        void sourceDataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight,
            const QVector<int> &roles);
        void sourceModelAboutToBeReset();
        void sourceModelReset();
        void sourceRowsAboutToBeInserted(const QModelIndex &parent, int start, int end);
        void sourceRowsAboutToBeMoved(const QModelIndex &sourceParent, int sourceStart,
            int sourceEnd, const QModelIndex &destinationParent, int destinationRow);
        void sourceRowsAboutToBeRemoved(const QModelIndex &parent, int first, int last);
        void sourceLayoutAboutToBeChanged(const QList<QPersistentModelIndex> &parents,
            QAbstractItemModel::LayoutChangeHint hint);
        void sourceRowsInserted(const QModelIndex &parent, int first, int last);
        void sourceRowsMoved(const QModelIndex &sourceParent, int sourceStart,
            int sourceEnd, const QModelIndex &destinationParent, int destinationRow);
        void sourceRowsRemoved(const QModelIndex &parent, int first, int last);
        void sourceLayoutChanged(const QList<QPersistentModelIndex> &parents,
            QAbstractItemModel::LayoutChangeHint hint);

    private:
        void initMaps(int size = -1);
        void updateMaps(int proxyIndex, int sourceIndex);
        int firstRow() const;
        int lastRow() const;
        int firstFreeRow() const;
        void applyPositions();
        void flushPendingChanges();
        void connectSignals(FolderModel *model);
        void disconnectSignals(FolderModel *model);

        bool m_enabled;
        FolderModel *m_folderModel;

        int m_perStripe;

        int m_lastRow;

        QModelIndexList m_pendingChanges;
        bool m_ignoreNextTransaction;

        QStringList m_positions;
        bool m_deferApplyPositions;
        QVariantList m_deferMovePositions;
        QTimer *m_updatePositionsTimer;

        QHash<int, int> m_proxyToSource;
        QHash<int, int> m_sourceToProxy;
        bool m_beginInsertRowsCalled = false; // used to sync the amount of begin/endInsertRows calls
};

#endif
